Innovations in dredging technology

After searching the market for innovative solutions to reducing its environmental impact from maintenance dredging, and looking to reduce its operational and maintenance costs, Harwich Haven Authority (HHA) developed Tiamat.

HHA is working towards achieving net zero by 2035, so needed to reduce the environmental impact of its operations in ports and harbours. And with maintenance dredging costing up to 25% of its annual revenue, it also required dredging technology that would save money.

Partnering with its specialist Dutch contractor, Maartens Van Oord, collectively they developed and built a cleaner and greener method of maintenance dredging, that is easy to deploy, adaptable and at a lower cost – Tiamat. HHA wanted to commercialise the offering and  established Haven Dredging to offer Tiamat as a solution, not only for Harwich, but for the entire world.

The standard Tiamat consists of a frame with two pumps that inject water into the sediment overlying the harbour bed, and another to extract diluted silt and release it up and into the water column. It is towed behind a small workboat or multi-cat of around 25-27 metres using an ‘A’-frame and is lowered into the water to the required depth.

So, how does Tiamat improve project efficiency, environmental performance and cost-effectiveness?

Tiamat dredges with nature by using the power of the tide and currents to self-replenish the estuarian system, through the natural re-suspension of sediment. Tiamat’s dredging technology ensures the sediment is placed back into the water column at the appropriate depth with the help of tidal currents, so the clarity and quality of the water are maintained.

A further innovation is that Tiamat is deployed by a standard small workboat rather than a large Trailing Suction Hopper Dredger (TSHD), so port authorities and dredging professionals can make considerable fuel savings, while the environment benefits from fewer carbon emissions.

Operating Tiamat can be up to 65% cheaper than using traditional dredging methods. The cost of using the 4,500 cubic metre Tiamat to clear a cubic metre of sediment is £1.00, while the cost of using a 7,500 cubic metre TSHD is about £2-3 per cubic metre of sediment.

In trials at Harwich Harbour, in the UK, Tiamat was typically operating continuously for 12 hours a day, while TSHDs undertaking maintenance dredging at Harwich Harbour will operate continuously 24 hours a day but will spend around 80% of the time sailing to and from the offshore disposal site and the four hours a day dredging. When operating Tiamat for 12 hours a day, it had a comparable daily production rate as a 4,500 cubic metre TSHD operating 24 hours a day.

Tiamat offers a flexible and effective method of dredging. Because of this, using Tiamat can reduce the cost of dredging and/or offer additional income streams for your business.

Another of Tiamat’s objectives is to be adaptable. Different ports, harbours and bodies of water around the world are different – whether we’re talking sediment composition, fluidity or accessibility. This means that to be a viable option, Tiamat needs to be able to be modified to meet these needs.

In America for example, there is widespread reporting of marine wildlife being disrupted by dredging. The Haven Dredging team developed a new version of Tiamat with additional low powered water jets at the front of Tiamat to alert marine life, such as turtles, to its presence before its arrival, encouraging them to move on before the dredging begins. Fondly known as the “turtle tickler”, this new adaptation is an important and progressive step forward for Haven Dredging in further supporting the environment and its inhabitants, and thus ensuring Tiamat is even less invasive than traditional methods.

As dredging needs are unique to individual ports and businesses, the innovative Tiamat’s adaptive and flexible technology can be tailored to these individual requirements. Its scalable technology ensures a bespoke design for each port or harbour – maximising the effectiveness of dredging, inclusive of all ports’ turbidity.

Tiamat’s innovative dredging technology offers a competitive advantage for port authorities and dredging professionals and benefits the bottom line and the planet.

Want to know how you can use this dredging technology in your project in ports and harbours? Contact Us now to find out more and discuss your needs.